Lighter-than-air vehicles are used in many different applications. In one well known application companies emblazon their corporate logo or trademark on a lighter-than-air vehicle, sometimes referred to as an airship, and operate the vehicle near large sporting events or in large metropolitan areas. Such advertising effectively generates increased sales. Lighter-than-air vehicles are also used in high altitude applications for the purpose of communications, weather monitoring, scientific research or military surveillance. This includes aerostats, which are held in place by a tether. In these high altitude applications it is known that the higher the vehicle can operate, the more area that can be viewed for surveillance purposes. Moreover, the higher the vehicle is situated, the more difficult it is to detect and destroy the vehicle.
Many known materials for these high altitude lighter-than-air vehicles are limiting inasmuch as they can only withstand a limited range of temperature variation. Moreover, the high altitude vehicles need to be able to withstand ozone degradation, extreme exposure to ultraviolet light, severe expansion and contraction in view of the wide temperature variations experienced in diurnal cycles, and extreme wind and weather forces. And, the lighter-than-air vehicles used for military operations are susceptible to radio frequency detection, laser targeting threats and the like. Of course, the aforementioned properties need to be combined with the standard desired properties for lighter-than-air vehicles, which include light weight, which allows increased payload for the vehicles, and good gas barrier properties to ensure long term deployment of the vehicle. Light weight laminate materials for lighter-than-air vehicles are described in U.S. patent application Ser. Nos. 10/388,772 and 11/443,327, both of which are hereby incorporated by reference. However, the combined properties of thermal management, shear modulus, helium permeability, static electricity dissipation, lightning protection, and long term durability at high altitudes have not previously been demonstrated.
Therefore, there is a need for lighter-than-air vehicles that use laminate or fabric materials with the above desirable properties and that are easy to manufacture and to conform to the desired shape.